Tripod jack



Dec. 18, 1956 s o 2,774,567

TRIPOD JACK Filed Nov. 20, 1953 United States Patent TRIPOD JACK RalphG. Shroyer, Columbus, Ohio, assignor of one-third to Harry L. Mellmanand one-third to Myer W. Mellman, Columbus, Ohio Application November20, 1953, Serial No. 393,310

Claims. (Cl. 254-99) This invention relates to jacks, and moreparticularly to improvements in jacks of the tripod type for use inservice stations, garages, farms, industry, et cetera.

The object of this invention is to provide a jack of the tripod typewherein the legs and the main frame members can be made of sheet metal,and at the same time be of strong and sturdy structure, effectivelyreinforced.

A further object of the invention lies in the provision of positivelyeffective means for camming the legs of the tripod outwardly when inoperating position and in camming them inwardly into close parallelismfor storing and transporting.

A further object of the invention is simplification of structureachieved by the provision of means integral with the sheet metal loadbearing main frame for the support of the load.

A further object of the invention is the provision of a handle so formedthat its path of travel is stopped at a point before it reachesa-vertical position, so that it is prevented from complete rotation andcannot travel over the top of the tripod.

A further object of the invention is the provision of means on thehandle for holding the handle in a fixed operative position when load isapplied, the strength of the means being proportional to the amount ofthe load applied.

Other objects and advantages reside in the construction of parts, thecombination thereof and the mode of operation, as will become moreapparent from the following description.

In the drawings, Figure 1 is a perspective view showing the device inoperative position.

Figure 2 is a cross sectional view taken on the line 2-2 of Figure 1.

Figure 3 is a rear elevational View of the top portion of the device,and showing the bearing in cross section.

Figure 4 is a fragmentary cross sectional view taken on the line 4-4 ofFigure 3, with leg members incomplete.

Figure 5 is a detail view as seen from the direction of the arrows 5-5in Figure 3. a

Figure 6 is a fragmentary top plan view, showing portions of leg membersincomplete.

Figure 7 is an elevational fragmentary view of the load bearing memberwith portions of the main frame member broken away.

The main frame or channel member 10 is of channel formation and theforward edges of its side walls 12 are each provided with flanges 13.The side walls 12 of the channel member 10 are provided adjacent theirupper ends with offset stamped out portions or cam surfaces 14. Theformation of these cam surfaces is best seen in Figure 4. Toward theforward edge of the channel side wall, the offset portion, as shown at11 in Figure 4, is extremely shallow, deepening as it progresses towardthe rear wall of the channel member 10, as shown at 14.

The side walls of the main frame member 10 are provided with reinforcingribs 18, stamped or otherwise ice formed into the sheet material of theframe. The rear wall of the channel member 10 is extended into a flap atits upper end, and is bent forwardly to a substantially right angularposition with respect to the side and rear Walls of the channel member10, and forms a seat 20 for a bearing assembly that will be more fullydescribed.

Openings 22 in the side walls of the main frame member 10 receive lugs21 of a plate 24. A foot member 26 is welded or otherwise secured to thelower end of the main frame or channel member 10. The foot member 26 maybe provided as desired with ribs 28, or any other suitable reinforcingmeans.

A pair of sheet metal or other angle irons 30 provide the second andthird legs of the tripod. These angle irons 30 are pivotally attached bymeans of rivets 16 to the outer surfaces of the side walls of thechannel member 10 at the positions of the slanting ofiset cam portions14. The angle irons 30 are provided with portions 31 substantiallyhorizontally disposed when the legs are spread, and welded or otherwisesecured to a pair of feet members 33.

Seated upon the upper surface of the seat member 20, and supported by itis a bearing assembly 32 comprised of a lower ball race 34, an upperball race 36, and ball bearings 38.

Seated upon the upper surface of the ball race 36 is a washer 40.

The members 20, 34, 36 and 40 are each provided with circular openingswhich are adapted to receive the upper end 41 of a lifting screw 44. Thesaid upper end 42 of the lifting screw 44 is provided with adiametrically disposed opening 41 which is adapted to receive ahorizontally disposed portion 48 of a handle 50.

The lower end of the lifting screw 44 is provided with a reducedcylindrical portion 45 forming a shoulder 47. The plate 24 also isprovided with a circular opening which receives the reduced portion 45,and functions as a seat for the shoulder 47.

The upper end 42 of the lifting screw 44 is provided with a plurality ofstops 46 which are punched out of the surface of the upper end member42, and are integral therewith. These stops limit the upward movement ofthe lifting screw.

The lifting screw 44 is prevented from downward movement by thehorizontally disposed portion 48 of the operating handle 50, which isreceived in the opening 41.

The portion 48 of the handle 50 rests upon the washer 40 and is providedwith a flattened portion 52. The operating handle 50 includes a handhold 54, a portion 56 of sufiicient length to provide leverage, apreviously indicated portion 48 disposed at a substantial right angle tothe portion 56, and a curved portion 58 disposed between, and connectingportions 48 and 56. .This formation can be more readily understood whenthe members 48 and 58 are considered as the vertical portion and thecurved portion respectively of a question mark.

A load lifting member 60 is formed of an integral portion of heavy sheetmaterial formed into a sleeve 66 adapted to receive the lifting screw 44in a loose sliding relationship, and a pair of flaps meeting at 68 andriveted or otherwise secured together, as shown at 70, 72 and 74.

The outwardly extending portions 76 of the flaps 68, together withnotches 64 therein, provide means for engaging and carrying the load tobe lifted, as for example, the bumper of a car.

An internally threaded sleeve 78 engages threads 43 of the lifting screw44. The outer surface of the sleeve 78 is of rectangular formation andis prevented from rotation by its close fit within the complementaryformation of the side and rear walls of the channel member 10. Thesleeve 78, therefore, travels upwardly or downwardly along the liftingscrew as the screw rotates, its direction depending upon the directionof rotation applied to the handle 54. The sleeve 66 rests upon and islifted and lowered with the upwardly and downward movement of the sleeve78. Thus, the load carrying member 76 receives its upward and downwardimpetus.

The various functions of most of the various parts have now becomeevident.

It will be seen that the cam surfaces 14 guide the legs 30 outwardlyaway from each other as they swing outwardly away from the main framemember 10. As they swing inwardly and approach the main frame member,they assume a relation of parallelism. In operative position, themembers 30 and become a tripod with legs extended and held positively inextended position. In a position of non-use, or for storing or carrying,the members 30 and 10 lie parallel and closely together.

The function of the peculiar formation of the right angularly disposedportions 48 and 56 of the handle 50, together with the interveningcurved portion 58 and the flattened portion 52, is as follows:

When load is applied at 60, the downward pressure causes the handle tocome to rest and remain with the flattened portion 52 downwardly andpressing upon the disc 40. The greater the load, the more firmly thisposition is maintained.

When the handle 50 is lifted, the curved portion 58 of the handle abutsthe disc 40 and the handle is stopped from continued travel over the topof the tripod.

A tripod jack is thus produced that is easily used, efficient and at thesame time low in cost of production.

Although the preferred embodiment of the device has been described, itwill be understood that within the purview of this invention variouschanges may be made in the form, details, proportion and arrangement ofparts, the combination thereof and mode of operation, which generallystated consist in a device capable of carrying out the objects setforth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

1. A duo-functional operating handle of round single piece bar stock foruse in a tripod jack having a sheet metal main frame member of channelformation comprising a rear wall and a pair of side walls, an aperturedflap member integral with the rear wall and overlying the upper end ofthe channel member, a bearing assembly seated upon said flap, a liftingscrew rotatably mounted within said channel member, a portion of saidlifting screw adjacent its upper end extending through openings in saidbearing assembly, said lifting screw being provided with a transversehole above the flap member, said operating handle being characterized bya horizontal portion on said handle extending through the transversehole in the lifting screw at the upper end thereof to thereby supportthe screw on the bearing assembly, a portion of the surface of thehorizontal portion of the handle being flattened to engage the uppersurface of the hearing assembly whereby load applied to said loadlifting means is transmitted through the horizontal portion of thehandle to the bearing assembly and thence to said flap, said flattenedportion holding the handle in a horizontal position when load is appliedto the lifting screw.

2. In a jack of the tripod type, a sheet metal main frame member adaptedto receive a lifting screw, and comprising a rear wall and a pair ofside walls, each of said side walls being provided adjacent its upperend with an offset bulging cam portion, said bulging cam portion beinginclined outwardly from the forward edge of the side wall, a pair oflegs, one of said legs being pivotally mounted on one side of the offsetbulging cam portion, and the other leg being pivotally mounted on theother bulging cam, said legs being cammed outwardly to extendedposition, and cammed inwardly towards the sheet metal main frame memberto a position of close parallelism when not in use.

3. In a jack of the tripod type, a sheet metal frame member receiving alifting screw, said main frame member being of channel formation andcomprising a rear wall and a pair of side walls, ribs on selected onesof said walls for reinforcement, said ribs terminating in spacedrelation from one end of the walls, stamped out cam portions integralwith and forming an integral part of the surface of said side walls atpoints adjacent their upper surfaces, said cam portions being inclinedoutwardly from the forward edge of the side walls, a leg pivotallymounted on the outer surface of each cam portion, each of said legsbeing cammed outwardly into positions of use, and inwardly into closeparallelism to a position of non-use.

4. A jack of the tripod type comprising a sheet metal main frame memberof channel formation including a rear wall and a pair of side walls, alifting screw mounted in said main frame member, a bulging cam portionstamped into and forming an integral part of each of the surfaces ofsaid side walls at positions adjacent their upper ends, said camportions being inclined outwardly from the forward edge of the sidewalls, a leg pivotally mounted upon the outer surface of each of saidside walls and being cammed outwardly as they are rearwardly swung topositions of use, and are cammed inwardly to positions of closeparallelism when not in use, a flap portion forming an integralextension of one of the Walls of said main frame at its upper end, bentat a substantial right angle thereto, a bearing assembly seated uponsaid flap, a single piece handle of round bar stock having ahorizontally disposed flattened portion secured to the upper end 0 fthelifting screw, said flattened portion holding the handle in a horizontalposition by the load upon the lifting screw, said flattened portionbeing then supported by the upper surface of the bearing assembly, saidhandle also provided with a portion of sufficient length to provideleverage for rotation, and a curved portion disposed between saidhorizontal portion and said leverage providing portions of said handle,said curved portion providing a stop for preventing the handle fromcomplete rotation over the top of said jack.

5. A duo-functional handle of round bar stock for use in a jack of thetripod type having a screw provided with a load supporting member, saidhandle comprising a horizontal portion supporting the screw extendingabove the frame of the jack, a portion for providing leverage forrotation disposed at a substantial right angle to the said horizontalportion, a curved portion disposed and forming connection between thesaid horizontal portion and said leverage providing portion, saidhorizontal portion of said handle resting on top of the frame of thejack and supporting the load upon the supporting member, said horizontalportion being provided with a flattened portion for aiding in seatingthe handle and holding the handle in horizontal position when a load issupported by the jack, said curved portion providing a stop forpreventing rotation of the handle over the top of said jack.

References Cited in the file of this patent UNITED STATES PATENTS818,114 Oster Apr. 17, 1906 2,326,023 Fredricksen Aug. 3, 1943 2,601,660Jarmicki June 24, 1952 2,608,382 Palka Aug. 26, 1952 2,609,178 Kearfulet al. Sept. 2, 1952 2,630,295 Lucker Mar. 3, 1953

